Merge branch 'dpll-zl3073x-add-ref-sync-pair-support'

Ivan Vecera says:

====================
dpll: zl3073x: add ref-sync pair support

This series adds Reference-Sync pair support to the ZL3073x DPLL driver.
A Ref-Sync pair consists of a clock reference and a low-frequency sync
signal (e.g. 1 PPS) where the DPLL locks to the clock reference but
phase-aligns to the sync reference.

Patches 1-3 are preparatory cleanups and helper additions:
- Clean up esync get/set callbacks with early returns and use the
  zl3073x_out_is_ndiv() helper
- Convert open-coded clear-and-set bitfield patterns to FIELD_MODIFY()
- Add ref sync control and output clock type accessor helpers

Patch 4 adds the 'ref-sync-sources' phandle-array property to the
dpll-pin device tree binding schema and updates the ZL3073x binding
examples.

Patch 5 implements the driver support:
- ref_sync_get/set callbacks with frequency validation
- Automatic sync source exclusion from reference selection
- Device tree based ref-sync pair registration

Tested and verified on Microchip EDS2 (pcb8385) development board.
====================

Link: https://patch.msgid.link/20260408102716.443099-1-ivecera@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 36 insertions, 7 deletions

diff --git a/Documentation/devicetree/bindings/dpll/dpll-pin.yaml b/Documentation/devicetree/bindings/dpll/dpll-pin.yaml
index 51db93b77306..1287a472f08f 100644
--- a/Documentation/devicetree/bindings/dpll/dpll-pin.yaml
+++ b/Documentation/devicetree/bindings/dpll/dpll-pin.yaml
@@ -36,6 +36,19 @@ properties:
     description: String exposed as the pin board label
     $ref: /schemas/types.yaml#/definitions/string
 
+  ref-sync-sources:
+    description: |
+      List of phandles to input pins that can serve as the sync source
+      in a Reference-Sync pair with this pin acting as the clock source.
+      A Ref-Sync pair consists of a clock reference and a low-frequency
+      sync signal.  The DPLL locks to the clock reference but
+      phase-aligns to the sync reference.
+      Only valid for input pins.  Each referenced pin must be a
+      different input pin on the same device.
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      maxItems: 1
+
   supported-frequencies-hz:
     description: List of supported frequencies for this pin, expressed in Hz.
 
diff --git a/Documentation/devicetree/bindings/dpll/microchip,zl30731.yaml b/Documentation/devicetree/bindings/dpll/microchip,zl30731.yaml
index 17747f754b84..fa5a8f8e390c 100644
--- a/Documentation/devicetree/bindings/dpll/microchip,zl30731.yaml
+++ b/Documentation/devicetree/bindings/dpll/microchip,zl30731.yaml
@@ -52,11 +52,19 @@ examples:
           #address-cells = <1>;
           #size-cells = <0>;
 
-          pin@0 { /* REF0P */
+          sync0: pin@0 { /* REF0P - 1 PPS sync source */
             reg = <0>;
             connection-type = "ext";
-            label = "Input 0";
-            supported-frequencies-hz = /bits/ 64 <1 1000>;
+            label = "SMA1";
+            supported-frequencies-hz = /bits/ 64 <1>;
+          };
+
+          pin@1 { /* REF0N - clock source, can pair with sync0 */
+            reg = <1>;
+            connection-type = "ext";
+            label = "SMA2";
+            supported-frequencies-hz = /bits/ 64 <10000 10000000>;
+            ref-sync-sources = <&sync0>;
           };
         };
 
@@ -90,11 +98,19 @@ examples:
           #address-cells = <1>;
           #size-cells = <0>;
 
-          pin@0 { /* REF0P */
+          sync1: pin@0 { /* REF0P - 1 PPS sync source */
             reg = <0>;
-            connection-type = "ext";
-            label = "Input 0";
-            supported-frequencies-hz = /bits/ 64 <1 1000>;
+            connection-type = "gnss";
+            label = "GNSS_1PPS_IN";
+            supported-frequencies-hz = /bits/ 64 <1>;
+          };
+
+          pin@1 { /* REF0N - clock source */
+            reg = <1>;
+            connection-type = "gnss";
+            label = "GNSS_10M_IN";
+            supported-frequencies-hz = /bits/ 64 <10000000>;
+            ref-sync-sources = <&sync1>;
           };
         };